2.5 - Latest technology in piezoelectric vibration- and pressure sensors and their benefits for measurement

etc2016 - 36. European Telemetry and Test Conference
2016-05-10 - 2016-05-12
Nürnberg, Germany
2. Sensors & AIM2016
S. Meyer - PCB Synotech GmbH, Hückelhoven (Germany)
85 - 89


To measure on turbines, engines and equipment at high temperatures vibrations or pressures, thesensors must meet extremely high demands. Special materials in the sensor design, for sensor housing and cable as well as the sensor element itself, is necessary to achieve extremely high operating temperatures. The new piezoelectric crystal UHT-12™ (Ultra High Temperature 1200°F/650°C) allowed an operating temperature of up to 700°C for sensors with charge output.
In addition, the measurement results are highly accurate, low noise (no popcorn noise) and temperature stable. Using this special synthetic crystal, also ICP® vibration sensors with extremely low temperature coefficients have been developed.
The result is reflected in an improvement in the accuracy of the amplitude response of the entire measurement chain over the entire temperature range from 29% down to 4% . This is a significant improvement in measurement uncertainty compared with sensors that use ferroelectric ceramics as measuring material.
With a clever choice of materials and manufacturing technologies are now also ICP® vibration sensors up to a working temperature of 180°C possible.
This challenge has been implemented in a miniature triaxial accelerometer with a weight of 1 gram. Integrated low-pass filter in ICP sensors find increasing popularity because it reduced the chance of amplifier saturation and increase the useable frequency range.
It saves so much trouble in applications where the sensor does not just see periodic signals, but also transient events or strokes. Against amplifier saturation by acoustic emission we can also integrate mechanically filters.